SM80591EIKD

Application Note: SM80591E High Efficiency, 1.5MHz, 1A Synchronous Step Down Regulator ` General Description Features   The SM80591E is a high efficiency 1.5MHz synchronous step down DC/DC regulator capable of delivering up to 1A output current. It can operate over a wide input voltage range from 2.5V to 5.5V and integrates main switch and synchronous switch with very low RDS(ON) to minimize the conduction loss.        The low output voltage ripple, the small external inductor and the capacitor sizes are achieved with 1.5MHz switching frequency. Ordering Information SM80591 □(□□□ ) Applications Package Code     Optional Spec Code Ordering Number SM80591EIKD 2.5V to 5.5V Input Voltage Range Low RDS(ON) for Internal Switches (Top/Bottom) 170mΩ /100mΩ High Switching Frequency 1.5MHz Minimizes the External Components Internal Soft-start Limits the Inrush Current 100% Dropout Operation Reliable Short Circuit Protection Output Auto Discharge Function RoHS Compliant and Halogen Free Compact Package: DFN1.1×0.9-6 Package type DFN1.1×0.9-6 Note -- Set Top Box USB Dongle Media Player Smart phone Typical Applications L1:2.2µH VIN : 2.5-5.5V CIN 10μF/6.3V RP G 100k RH 100k PG COUT Cff 22pF 10μF/6.3V FB Efficiency vs. Output Current (IOUT=0~1A, L=2.2µH/0420CDMCCDS-2R2MC) 100 RL 49.9k EN ON/ OFF VOUT :1.8V LX VIN 90 80 Efficiency (%) GND Figure1. Schematic Diagram 70 60 50 40 30 VIN =3.3V, VOUT =1.8V VIN =4.2V, VOUT =1.8V VIN =5.0V, VOUT =1.8V 20 Inductor and COUT Selection Table VOUT [V] 1.2 1.8 3.3 L [µH] 1.5 2.2 1.5 2.2 2.2 4.7 COUT [µF] 10 √ ☆ √ ☆ ☆ 10 0 22 √ √ √ √ √ 0.001 0.01 0.1 Output Current (A) Figure2. Efficiency vs. Output Current Note: ‘☆’ means recommended for most applications. AN_SM80591E Rev. 0.9 © 2021 Silergy Corp. Silergy Corp. Confidential- Prepared for Customer Use Only 1 All Rights Reserved. 1 SM80591E Pinout (Top View) LX 1 6 VIN EN 2 5 GND PG 3 4 FB (DFN1.1×0.9-6) Top Mark: dxyz (device code: d, x=year code, y=week code, z= lot number code) Pin Name Pin Number Pin Description LX 1 Inductor pin. Connect this pin to the switching node of the inductor. EN 2 Enable control. Pull high to turn on. Do not leave it floating. PG 3 FB 4 GND 5 Ground pin. VIN 6 Input pin. Decouple this pin to the GND pin with at least a 10µF ceramic capacitor. Power good indicator (open drain output). Low if the output < 90% or the output >120% of regulation voltage; High otherwise. Connect a pull-up resistor to the input. Output feedback pin. Connect this pin to the center point of the output resistor divider (as shown in Figure 1) to program the output voltage: V OUT=0.6×(1+RH/RL). Absolute Maximum Ratings (Note 1) Supply Input Voltage------------------------------------------------------------------------------------------------- -0.3V to 6.0V EN, FB, PG Voltage------------------------------------------------------------------------------------------ -0.3V to VIN + 0.6V LX Voltage----------------------------------------------------------------------------------------- -0.3V (*1) to 6.0V (*2) (*3) Power Dissipation, P D @ TA = 25°C ------------------------------------------------------------------------------- 1W Package Thermal Resistance (Note 2) θ JA --------------------------------------------------------------------------------------------------------------- 100°C/W θ JC ----------------------------------------------------------------------------------------- ------------------------ 25°C/W Junction Temperature Range ------------------------------------------------------------------------------------ -40oC to 150°C Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------------- 260°C Storage Temperature Range ----------------------------------------------------------------------------------- -65°C to 150°C (*1) LX Voltage Tested Down to -3V